KR20040039749A - Latching mechanism of dual capacity compressor - Google Patents

Abstract

PURPOSE: A latching element for double capacity compressor is provided to prevent an outer peripheral surface of an eccentric pin from being scratched, and accurately process an inside diameter of an eccentric sleeve. CONSTITUTION: An eccentric pin(32) is formed at a crank shaft(30) rotated by a motor part, and rotates eccentrically with the center of rotation of the crank shaft. An eccentric sleeve has an eccentric through-hole for passing the eccentric pin through, and rotates integratedly with the eccentric pin in a predetermined direction. A connecting rod(42) has one end connected with the eccentric pin in a state of inserting the eccentric sleeve, and the other end connected with a piston for converting rotary motion of the crank shaft into rectilineal reciprocation. An eccentric weight part(36) is installed at the eccentric sleeve, having an outside diameter larger than an outside of the eccentric sleeve, and provides rotary force to the eccentric sleeve according to the rotary direction of the crank shaft. A latching pin(38) has one end protruded from an outer surface of the eccentric pin after passing through the eccentric pin, and rotates the eccentric pin and the eccentric sleeve integratedly by stopping the rotation of the eccentric sleeve at a specific position. Interference evasive chamfers are formed between the eccentric pin and the eccentric sleeve for preventing interference between the eccentric pin and the eccentric sleeve.

Description

Latching mechanism of dual capacity compressor

The present invention relates to a hermetic compressor, and more particularly, to a latching mechanism of a double displacement compressor capable of changing the compression capacity by varying the stroke length of the piston according to the rotational direction of the crankshaft.

The dual displacement compressor is a kind of reciprocating compressor whose compression capacity is changed by changing the stroke distance of the piston connected to the crankshaft by the connecting rod according to the rotational direction of the crankshaft. Such a dual capacity compressor may increase the efficiency of the compressor by adjusting the compression capacity according to the size of the refrigeration load in the apparatus using a refrigeration cycle, such as a refrigerator.

As such a double capacity compressor, there is US Patent No. 4,236,874, which will be described with reference to FIGS. 1 and 2. As shown in the figure, the crankshaft 1 which is rotated integrally with the rotor of the motor unit is provided with an eccentric portion 3 to be eccentric with its rotation center 1a. Reference numeral 3a is the center of the eccentric portion 3.

An eccentric sleeve 4 is provided to surround the outer circumferential surface of the eccentric portion 3. The eccentric sleeve 4 is composed of a first eccentric portion 4a and a second eccentric portion 4b, an inner circle formed by the first eccentric portion 4a and the second eccentric portion 4b. The circle in which the core 3 is located is eccentric in the center of the eccentric sleeve 4 itself. Here, the inner circle of the eccentric sleeve 4 is formed to be biased by the second eccentric portion 4b, and when viewed in plan view, the first eccentric portion 4a has a relative distance from its outer circumferential surface to the inner circle. Large and the second eccentric portion 4b is formed relatively small. This eccentric sleeve 4 has the center of rotation 3a of the eccentric portion 3 as the center of rotation.

A connecting rod 5 is connected to the eccentric portion 3, and the eccentric sleeve 4 is positioned between the inner circumferential surface of the connecting rod 5 and the eccentric portion 3. Here, the one side where the eccentric portion 3 and the eccentric sleeve 4 are in contact with each other is buffered by a predetermined length along the outer circumference of the eccentric portion 3 and the inner circumference of the first eccentric portion 4a of the eccentric sleeve 4. Grooves 11 and 12 are formed, and latching pins 6 are installed to penetrate the buffer grooves 11 and 12 to prevent relative rotation between the eccentric portion 3 and the eccentric sleeve 4. do.

The connecting rod 5 is connected to the piston 7 provided in the cylinder 8 to convert the rotation of the crankshaft 1 into a linear reciprocating motion of the piston 7. The connecting rod 5 has a large diameter 5 'connected to the eccentric portion 3 of the crankshaft 1 with the eccentric sleeve 4 interposed therebetween.

In the prior art having such a configuration, the stroke distance of the piston 7 is adjusted by the eccentric sleeve 4 which rotates with respect to the center 3a of the eccentric portion 3 of the crankshaft 1, which is a refrigeration load. Is required to rotate the crankshaft 1 clockwise with reference to FIG. 2 and when the refrigeration load is required to rotate the crankshaft 1 counterclockwise.

That is, A and B of FIG. 2 show the case where the crankshaft 1 is rotated clockwise in the case of large capacity, A is a case where a piston is in top dead center, and B is a case where a piston is in bottom dead center. In this case, since the eccentricity is maximum, the stroke length L is maximum.

2C and D show the case where the crankshaft 1 is rotated counterclockwise in the case of small capacity, C is the case where the piston is at the bottom dead center, and D is the case where the piston is at the top dead center. In this case, since the eccentricity is minimum, the stroke length L 'is minimized.

At this time, the latching pin (6) according to the relative rotation of the eccentric portion (3) and the eccentric sleeve (4) in the buffer groove (11, 12) whenever the rotation direction of the crankshaft (1) is changed. As the position is changed, the relative position between the eccentric portion 3 and the eccentric sleeve 4 is fixed.

However, the prior art having such a configuration has the following problems.

In the prior art as described above, since the entire latching pin 6 is positioned in the buffer grooves 11 and 12 and its outer circumferential surface is in contact with the inner surfaces of the buffer grooves 11 and 12, a lot of wear occurs and a lot of input loss occurs. have.

In addition, the outer surface of the eccentric portion 3 and the inner surface of the eccentric sleeve 4 corresponding thereto should be smoothly processed since the relative rotation is possible. However, the part that is precisely processed by the presence of the buffer groove 12 formed on the outer surface of the eccentric portion 3 and the buffer groove 11 formed on the inner surface of the eccentric sleeve 4 is the eccentric portion 3 and the eccentric. The outer circumferential surface or the inner circumferential surface of the sleeve 4 does not become the entire portion, except for the buffer grooves 11 and 12. As such, the part to be precisely processed does not become symmetrical to the whole workpiece, which causes a relatively low accuracy of machining.

In addition, the presence of the buffer grooves (11, 12) may cause scratches on the eccentric sleeve (4) and the eccentric portion (3), which is a counterpart, so that the operation reliability of the compressor is inferior when used for a long time.

Accordingly, an object of the present invention is to solve the problems of the prior art as described above, the interference between components in a double displacement compressor having a latching structure capable of fixing the eccentric sleeve in a desired position according to the rotational direction of the crankshaft. Minimizing wear caused by

1 is a cross-sectional view showing a latching mechanism of a conventional double displacement compressor.

Figure 2 is an operating state showing that the latching mechanism is operated in the double capacity compressor according to the prior art.

Figure 3 is a perspective view showing a preferred embodiment of the latching mechanism of the double displacement compressor according to the present invention.

4 is a cross-sectional view showing the configuration of an embodiment of the present invention.

Figure 5a is a plan sectional view showing the main portion of the embodiment of the present invention.

Figure 5b is a side cross-sectional view showing the main portion of the embodiment of the present invention.

6 is an operational state diagram illustrating the operation of the embodiment of the present invention.

7 is a cross-sectional view showing the configuration of another embodiment of the present invention.

8 is a plan sectional view showing a configuration of the embodiment shown in FIG.

Explanation of symbols on the main parts of the drawings

20: frame 22: motor portion

24: cylinder 26: piston

30: crankshaft 32: eccentric pin

34: eccentric sleeve 36: eccentric mass part

38: latching pin 40: latching spring

42: connecting rod 43: large diameter

44: Small diameter 50,50 ': Avoidance step

According to a feature of the present invention for achieving the object as described above, the present invention is provided in the crankshaft rotated by the motor portion and the eccentric portion which is rotated eccentrically with the rotation center of the crankshaft, and the through hole through which the eccentric portion is penetrated. Eccentric sleeves are formed eccentrically and installed in the through-hole to be seated and rotated in a predetermined direction relative to the eccentric portion in accordance with the rotational direction of the crankshaft rotated integrally, one end portion with the eccentric sleeve interposed in the state A connecting rod connected to the eccentric portion and the other end connected to the piston and converting the rotational movement of the crankshaft into a linear reciprocating motion of the piston, and provided in the eccentric sleeve with an outer diameter larger than the outer diameter of the eccentric sleeve to rotate the crankshaft. An eccentric mass part which provides a rotational force by centrifugal force to the eccentric sleeve along the direction, and at least once A latching pin through which the eccentric portion penetrates the eccentric portion and protrudes on the outer surface of the eccentric portion, and the rotation of the eccentric sleeve by the centrifugal force stops at a specific position so that the eccentric portion and the eccentric sleeve are integrally rotated between the eccentric portion and the eccentric sleeve. It is provided to include an interference avoidance step to prevent the interference between the eccentric portion and the eccentric sleeve.

The interference avoidance step is formed around the upper outer peripheral surface of the eccentric portion.

The interference avoidance step is formed around the upper outer peripheral surface of the eccentric sleeve.

The upper surface of the interference avoidance step is located at a lower position than the lower end of the locking end provided in the eccentric sleeve.

According to the present invention having such a configuration, while providing a latching structure requiring a relatively small input, the wear caused by the interference between the eccentric sleeve and the eccentric pin of the crankshaft is reduced and the manufacturing of the eccentric sleeve and the eccentric pin becomes easier. have.

Hereinafter, a preferred embodiment of the latching mechanism of a double displacement compressor according to the present invention will be described in detail with reference to the accompanying drawings.

Figure 3 shows a preferred embodiment of the latching mechanism of a double displacement compressor according to the present invention in a perspective view, Figure 4 shows the configuration of the embodiment of the present invention in a cross-sectional view, Figure 5 shows the main configuration of the embodiment of the present invention in a cross-sectional view, respectively Is shown.

As shown in these drawings, the frame 20 is installed inside the sealed container (not shown) constituting the appearance of the compressor, and the motor unit 22 is provided under the frame 20. The motor unit 22 is composed of a stator fixed to the frame 20 and a rotor installed in the center of the stator to rotate by electromagnetic interaction with the stator.

A cylinder 24 is provided at one side of the frame 20, and the piston 26 is installed in the cylinder 24, that is, the compression chamber, so as to linearly reciprocate. Crank shaft 30 is installed to penetrate one side of the frame 20 up and down. The lower end of the crankshaft 30 is pressed into the rotor of the motor unit 22 is rotated integrally. Reference numeral 31 is an oil channel.

An upper end of the crank shaft 30 is provided with an eccentric pin 32 at a position away from the center of rotation of the crank shaft 30. A counterweight 33 is provided on the crankshaft 30 to solve the rotational imbalance of the crankshaft 30 by the eccentric pin 32.

The eccentric sleeve 34 is formed in a cylindrical shape so that the center of the through hole 35 penetrating the inside is in a position deviated from the center of the eccentric sleeve 34 itself. Therefore, the thickness between the outer circumferential surface of the eccentric sleeve 34 in the inner surface of the through hole 35 of the eccentric sleeve 34 is formed different from each other. At this time, it is preferable that the through hole 35 is formed so that the thickest part and the thinnest part exist at positions facing each other. The eccentric sleeve 34 is installed on the eccentric pin 32 so that the eccentric pin 32 is seated in the through hole 35. The height of the eccentric sleeve 34 is formed lower than the height of the eccentric pin (32).

An eccentric mass 36 is provided at the upper end of the eccentric sleeve 34 so as to protrude further in the centrifugal direction than the outer diameter of the eccentric sleeve 34. The eccentric mass portion 36 is formed in a plate shape having a substantially circular shape and a predetermined thickness, and the eccentric sleeve 34 is provided at a position eccentrically from the center thereof.

The eccentric mass portion 36 serves to cause the eccentric sleeve 34 to be rotated to a desired position by generating the centrifugal force in the eccentric sleeve 34 according to the rotation of the crankshaft 30. The eccentric mass portion 36 may be integrally formed at the upper end of the eccentric sleeve 34 or separately formed and installed on the eccentric sleeve 34. When the eccentric mass portion 36 is manufactured separately, it can be press-fitted into the eccentric sleeve 34 or mounted using a key.

Protruding ribs 37 are formed stepwise at an upper end of the eccentric sleeve 34 so as to protrude from the upper surface of the eccentric mass 36. The protruding rib 37 corresponds to the planar shape of the eccentric sleeve 34 as shown in FIG. 5A and is formed only in a predetermined circumferential angle range. Both ends of the protruding rib 37 form engaging ends 37a and 37b. The latching ends 37a and 37b are the portions on which the latching pins 38 to be described below are hooked.

A latching pin 38 is installed on the eccentric pin 32. The latching pin 38 is installed to penetrate the upper end of the eccentric pin 32 in the transverse direction, and one end thereof protrudes out of the eccentric pin 32. The latching pin 38 is formed to have a length larger than the outer diameter of the eccentric pin 32 and smaller than the outer diameter of the eccentric sleeve 34. The latching pin 38 is supported by a latching spring 40 in the eccentric pin 32. Therefore, only one end of the latching pin 38 normally protrudes to the outer surface of the eccentric pin 32. During the rotation of the crankshaft 30, both ends thereof move to protrude to the outer surface of the eccentric pin 32 while overcoming the elastic force of the latching spring 40 by the centrifugal force. Reference numeral 39 is a stopper for preventing the latching pin 38 from being removed from the eccentric pin (32).

One end of the connecting rod 42, that is, the large diameter 43, is connected to the eccentric pin 32 with the eccentric sleeve 34 interposed therebetween. At this time, the inner surface of the large diameter 43 and the outer surface of the eccentric sleeve 34 has a predetermined clearance to enable relative rotation. The small end diameter 44 of the other end of the connecting rod 42 is connected to the piston 26 by a piston pin 45.

Meanwhile, in the present embodiment, the interference avoidance step 50 is formed around the inner circumferential surface of the upper end of the eccentric sleeve 34. The interference avoidance step 50 is formed around the upper end of the through hole 35 of the eccentric sleeve 34, the outer surface of the eccentric pin 32 is inserted into the through hole 35 and the eccentric sleeve 34 ) Is to prevent interference with the protruding rib 37 and its engaging ends 37a and 37b. In the interference avoidance step 50 portion, the inner diameter is formed to be larger than the inner diameter of the through hole 35.

Next, Fig. 7 and Fig. 8 show another embodiment of the present invention. In the present embodiment, the interference between the eccentric sleeve 34 and the eccentric pin 32, that is, the protruding rib 37 provided at the upper end of the eccentric sleeve 34 and its engaging ends 37a and 37b and the eccentric pin ( Interference avoidance step 50 'to prevent the interference between the 32 is formed surrounding the upper outer peripheral surface of the eccentric pin (32).

In other words, the interference avoidance step 50 'is formed so as to surround the upper outer peripheral surface of the eccentric pin 32. At this time, the upper surface of the interference avoidance step 50 'should be at least at a lower position than the lower ends of the engaging ends 37a and 37b.

It will be described below that the latching mechanism of the double displacement compressor according to the present invention having the configuration as described above is operated.

In the present invention, the crankshaft 30 is selectively rotated in both directions by the motor unit 22. For example, as shown in FIG. 6A, when the crankshaft 30 rotates counterclockwise, the eccentric pin 32 rotates while drawing a circular trajectory about the center of rotation of the crankshaft 30. .

By such rotation, the eccentric sleeve 34 is rotated in a specific direction while the centrifugal force is applied by the eccentric mass portion 36. Such rotation of the eccentric sleeve 34 is rotated until the engaging ends 37a and 37b are caught by the latching pin 38, as shown in FIG. 6A.

In addition, as shown in FIG. 4, the latching pin 38 has the centrifugal force generated by the rotation of the crank shaft 30 in the state where only one end thereof protrudes from the eccentric pin 32. One end portion which protrudes while overcoming the elastic force is slightly entered, and the other end portion which does not protrude is protruded so that both ends of the latching pin 38 are caught by the engaging ends 37a and 37b, respectively.

In this state, the eccentric sleeve 34 rotates integrally with the eccentric pin 32, and in particular, a relatively thick portion of the eccentric sleeve 34 is in the piston 26 direction, The part is opposite to the piston 26 with respect to the eccentric pin 32. In other words, the through hole 35 of the eccentric sleeve 34 is located at a position relatively far from the piston 26. In this case, the stroke length of the piston becomes relatively long.

Next, when the crankshaft 30 is rotated in the clockwise direction by the motor unit 22, the eccentric pin 32 rotates while drawing a circular trajectory around the center of rotation of the crankshaft (30). .

By such rotation, the eccentric sleeve 34 is rotated in the opposite direction to the case described above while the centrifugal force is acted by the eccentric mass 36, so that both ends of the latching pin 38 are shown well in FIG. 6B. As shown, it is rotated until it engages the said locking end 37a, 37b.

In this state, the eccentric sleeve 34 rotates integrally with the eccentric pin 32, and in particular, a relatively thin portion of the eccentric sleeve 34 is in the direction of the piston 26, The part is opposite to the piston 26 with respect to the eccentric pin 32. In other words, the through hole 35 of the eccentric sleeve 34 is in a position relatively close to the piston 26. In this case, the stroke length of the piston becomes relatively short. Of course, the stroke length of the piston is shorter and longer depending on the rotational direction of the crankshaft may be designed on the contrary.

Thus, since the stroke distance of the piston 26 is changed according to the position of the eccentric sleeve 34, the capacity to compress the working fluid by the piston 26 will be different.

On the other hand, in the present invention, in order to prevent scratching of the corresponding outer circumferential surface of the eccentric pin 32 due to interference between the eccentric pin 32 and the locking end (37a, 37b) of the eccentric sleeve 34, Interference avoidance steps 50 and 50 'are formed such that the upper surface is formed at least at a lower position than the lower ends of the engaging ends 37a and 37b of (34). Due to the presence of such interference avoidance steps 50 and 50 ′, scratches can be prevented from occurring on the outer circumferential surface of the eccentric pin 32.

In addition, since the interference avoidance step 50 is formed in the eccentric sleeve 34, the portion to be processed precisely in the inner diameter surface of the eccentric sleeve 34 is formed symmetrically. Therefore, the precision machining surface of the eccentric sleeve 34 can be formed more easily and precisely.

Of course, in the embodiment shown in Figures 7 and 8, the portion to be precisely processed in the inner surface of the eccentric sleeve 34 corresponding to the interference avoidance step 50 'is present in the eccentric pin 32 is formed symmetrically It may also be able to form the inside of the eccentric sleeve 34 more easily and precisely.

In the latching mechanism of the dual displacement compressor according to the present invention as described in detail above, the eccentric sleeve is rotated to a desired position by the centrifugal force generated by the eccentric mass according to the rotational direction of the crankshaft, and the eccentric pin and Rotating integrally adjusts the stroke distance of the piston connected to the connecting rod.

In the present invention, since the interference avoidance step is formed around the upper inner circumferential surface of the eccentric sleeve or the upper outer circumferential surface of the eccentric pin, the phenomenon that the outer circumferential surface of the eccentric pin is prevented from being scratched by the locking end of the eccentric sleeve has the advantage of minimizing the wear of parts. have.

In addition, in the present invention, since the region to be precisely processed on the inner surface of the eccentric sleeve is formed symmetrically, the machining operation can be made relatively easy to increase the inner diameter shape accuracy of the eccentric sleeve.

Claims (4)

An eccentric part which is provided on the crank shaft which is rotated by the motor part and which is rotated eccentrically with the rotation center of the crank shaft, An eccentric sleeve which is formed so that the through-hole penetrating the eccentric part is eccentrically and is installed so that the eccentric part is seated in the through-hole and rotates in a predetermined direction with respect to the eccentric part in accordance with the rotational direction of the crankshaft; A connecting rod connected to the eccentric portion with one end interposed between the eccentric sleeve and the other end connected to the piston to convert rotational movement of the crankshaft into linear reciprocating movement of the piston, An eccentric mass part provided in the eccentric sleeve having an outer diameter larger than that of the eccentric sleeve and providing a rotational force by centrifugal force to the eccentric sleeve according to the rotational direction of the crankshaft; A latching pin at least one end of which penetrates the eccentric to protrude on the outer surface of the eccentric, and the rotation of the eccentric sleeve by the centrifugal force stops at a specific position so that the eccentric and the eccentric sleeve are integrally rotated; A latching structure of a dual displacement compressor comprising an interference avoidance step provided between the eccentric portion and the eccentric sleeve to prevent interference between the eccentric portion and the eccentric sleeve. The latching structure of a dual displacement compressor according to claim 1, wherein the interference avoidance step is formed around an upper outer circumferential surface of the eccentric portion. The latching structure of a double displacement compressor according to claim 1, wherein the interference avoidance step is formed around an upper circumferential surface of the eccentric sleeve. The latching structure of a double displacement compressor according to claim 2 or 3, wherein the upper surface of the interference avoidance step is located at a lower position than a lower end of the locking end provided in the eccentric sleeve.